Ratko Mladic has been allowed to visit the grave of his daughter who committed suicide during the Bosnia war of the 1990s.

Mladic, who is is awaiting extradition to a UN tribunal, made the visit early on Tuesday morning under tight security, said Serbia's deputy war crimes prosecutor, Bruno Vekaric. Mladic is expected to be extradited to the tribunal in The Haguelate on Tuesday or early on Wednesday.

"We didn't announce his visit to the grave because it is his private thing and because it represented a security risk," Vekaric said. "The operation lasted for 20 minutes and passed without a glitch."

Europe's most wanted war crimes fugitive was arrested on Thursday in a village north of Belgrade after 16 years on the run. Mladic is charged by the tribunal for atrocities committed by his Serb troops during Bosnia's 1992-95 war.

His 23-year-old daughter Ana killed herself in 1994 with her father's pistol. Media reports at the time said she did it because of depression caused by her father's role in the war. Mladic has always claimed she was killed by his wartime enemies.

Mladic visited the red marble grave with a cross at a graveyard on a hill in a Belgrade suburb. There, he left a lit candle and a small white bouquet of flowers with a red rose in the middle.

Mladic's lawyer said on Monday that he has formally filed an appeal against the former general's extradition – a move that will likely delay his handover to The Hague until Tuesday night or Wednesday morning. Milos Saljic also has asked for several doctors to examine the 69-year-old Mladic, who is said to have suffered at least two strokes.

Saljic said he mailed his appeal from an unidentified post office in Belgrade on Monday. Court officials will now need to wait for it to arrive and review it before ruling on the appeal.

Vekaric accused Mladic of using delaying tactics and said nothing should prevent his extradition to the tribunal. The prosecutor said no one will be informed when Mladic will be transported from his prison and flown to the Netherlands "because of security risks".

On Monday, the Serbian president, Boris Tadic, rejected speculation that authorities had known of Mladic's hiding place and delayed his arrest to coincide with a visit by EU foreign policy chief Catherine Ashton. The rumours have persisted because Mladic was found living not far from the capital, Belgrade, with relatives who share his last name.

"Any such comment makes no sense," Tadic said. "The truth is that we arrested Ratko Mladic the moment we discovered him."

The president also said it's time for the European Union to do its part by boosting his nation's efforts to join the bloc, arguing the arrest of Mladic proves it is serious about rejoining the international fold. "I simply ask the EU to fulfil its part," he said. "We fulfilled our part and we will continue to do so."

The EU had repeatedly said that Serbia could begin pre-membership talks only after it arrested the wartime Bosnian Serb commander. Some EU nations have already said Serbia needs to do more, including arresting its last fugitive, Goran Hadzic, who led Croatian Serb rebels during the war.